Conventional systems and methods typically test Wavelength Division Multiplexing (“WDM”) systems by performing wavelength scanning of the channels in the WDM system while the WDM system is out of service. In order to test in-service WDM systems, i.e., those in the field, one or more channels are typically taken out of service thereby reducing the efficiency of the system. Additionally, a channel may have a noticeable change in power when wavelength scanning is performed on the channel. The change in power may occur because the scanning nature of the signal may cause the signal to be inside of the channel at a first time and slightly or severely outside of the channel at a second time. The optical amplifiers may have a channel power monitoring function that monitors the power in one or more channels and adjusts the amplifier gain to compensate for a change in power. Accordingly, because the power of the channel being scanned may vary, optical amplifiers in the WDM system may rapidly and/or repeatedly adjust gain to compensate for the change in power thereby possibly resulting in system instability. Further, upon determining that a channel does not have at least a minimum amount of power, the optical amplifier may block the channel to reduce interference to other WDM channels performing data transmission or reception. Blocking the channel may reduce the efficiency of the system.
Additionally, conventional systems and methods for performing tests that require multiple channels to be tested have not performed the testing simultaneously over the channels. Conventional approaches to testing multiple channels includes taking a channel out of service, performing wavelength scanning on the channel, measuring the output of the channel, and repeating the process with another channel. The measured outputs are then averaged. This approach to testing multiple channels may result in unreliable measurements because the tests are not performed simultaneously.